Clinical impact of perfusion balloon for ST-segment elevated myocardial infarction: RYUSEI study

Abstract Background Drug-eluting stents have significantly contributed to reducing mortality in patients with ST-segment elevation myocardial infarctions (STEMIs), but slow flow/no-reflow phenomenon and in-stent restenosis are still clinical problems. On the other hand, perfusion balloons (PBs) can compress thrombi and ruptured plaque for long inflation without ischemia and can be used as a delivery device for infusion of nitroprusside to distal risk area during ballooning. Purpose We conducted RYUSEI (Reduction of risk bY perfUsion balloon for ST-segment Elevated myocardial Infarction) study to evaluate whether PBs before stenting are more effective than conventional stenting for STEMIs. Methods We divided consecutive patients with STEMIs who underwent optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) into PB group who were treated with PBs before stenting and the conventional PCI (CP) group. In PB group, we inflated PB at the culprit lesion for five minutes to compress thrombi and ruptured plaque as a pre-stent lesion modification. In addition, an intra-coronary injection of nitroprusside (total dose: 120 µg; slow bolus injection of 24 µg/5mL every minute [5 times]) into the distal vascular bed to the culprit lesion through the PB was performed during a 5-minute PB ballooning. We compared clinical results including slow flow/no-reflow phenomenon, OCT findings, and one-year clinical events including cardiac death, target vessel-related myocardial infarctions, target lesion revascularization and stent thromboses between the two groups. Results We finally analyzed 34 patients in PB group and 90 in CP group. After propensity score matching, PB and CP groups consisted of 23 patients, respectively. In the propensity score-matched cohort, there were no significant differences of the patients’ backgrounds and lesion and procedural characteristics between the two groups. In the cohort, regarding post PCI angiographic and OCT findings, the incidence of slow flow/no-reflow phenomenon and maximum protrusion area detected by OCT were significantly lower (P=0.047 and P=0.019, respectively) and TIMI flow grade 3 was significantly higher (P=0.022) in the PB group than CP group while the other parameters were similar (Table). Kaplan-Meier analysis revealed a significantly better one-year clinical outcome in PB group than CP group (p=0.038) (Figure). Conclusions The RYUSEI study revealed a pre-stent lesion modification in addition to nitroprusside infusion using PB is useful to achieve better clinical course in STEMI patients.Post PCI Angiographic and OCT FindingsComparison of One-year Clinical Outcome